Apparatus for plicating tubing



2 Sheets-Sheet l IN VEN TOR. 605 TA V F/PEc/NQZ v 8% fw/ A rog/Ey G.FREUND, llI

APPARATUS FOR PLICATNG TUBING Feb. 20, 1951 Flled Dec 6 1946 Feb. 20,1951 G. FREUND, ll

APPARATUS FOR PLICATING TUBING Filed Dec. 6, 1946 2 Sheets-Sheet 2AINVENTOR.. Gusr vF/esa/voll BY JV A TTONEK Patented Feb. 20, 195.1

APPARATUS FOR PLICATING TUBING Gustav Freund, II, Highland Park, Ill'.,assigner to The Visking Corporation, Chicago, Ill., a corporation ofVirginia Application December 6, 1946, Serial No. 714,451

(o1. ca -1) 9 Claims.

This invention relates to a new and improved method of and apparatus forplicating tubing. More particularly, it relates to a method of andapparatus for producing continuous lengths of plicated seamless tubing.

. Recently, there has been devised a process wherein a plastic isextruded from a melt to form a thin-walled 'seamless tubing which iscollected in flattened condition on a reel. In such flattened tubings,the top and bottom panels have a tendency to stick together andconsiderable difficulty is encountered in separating the panels so thatthe tubing can be expanded for use. After considerable research andexperimentation, it was found that if the flattened tubing had plcatedsides, the flattened tubing could be easily opened. More particularly,it was found that when either leg of a plicated side was pulled awayfrom the other, and this can be very easily done, an opening wasprovided at the end of the tubing which permitted the insertion of afinger or tool whereby such opening could be enlarged with no diiiculty.For economic purposes, it is highly desirable that continuous lengths oftubing be plicated. However, there is no method in the prior art whichdiscloses producing continuous lengths of plicated tubing from apreformed seamless tubing in the flattened state, nor any apparatustherefor. Y

An object of this invention is to provide a method of and apparatus forproducing continuous lengths of plicated tubing.

Another object of this invention is to provide a method of and apparatusfor producing continuous lengths of plicated tubing from preformedcontinuous lengths of' flattened seamless tubing.

Other and additional objects will become apparent hereinafter. e

The objects of the invention are accomplished, in general, by graduallyattening a seamless tubing inflated with a gaseous medium andsimultaneously infolding the tubing on opposite sides thereof to producea flattened tubing wherein the top and bottom panels are at and theopposite sides plicated. The legs of the plicated sides can be equal,but alternatively, however, they are made of uneven lengths whereby oneof such legs projects beyond the other so that it can be manuallygripped for initiating the opening of the attenedV tubing.

In one form of an apparatus for carrying out the method and whichconstitutes one part of this invention, tubing is fed between two pairsof squeeze rolls and a bubble of a gaseous medium is entrapped or sealedoff in the section of the tubing between the two pairs of rolls, wherebythe tubing is inflated. The bubble of gaseous medium is isolated in thetubing between the two pairs of squeeze rolls and, as the continuoustubing is fed from a suitable source of supply between 2 these two pairsof rolls. the gaseous medium ad vances bodily therethrough whileremaining substantially constant in quantity, with the result that thesuccessive sections of the tubing passing between said' rolls aresuccessively inflated. The two pairs of rolls are preferably driven atthe same peripheral speed so that the tubing is not stretched in itspassage therebetween. Means are provided to maintain the squeeze rollsof each pair in contact with each other so that the gaseous medium canbe entrapped in the tubing between the two pairs of rolls.

Between the two pairs of rolls and in the path of travel of the inflatedtubing, there is provided a plicating funnel through which the tubingpasses. The plicating funnel is of such a construction, as willhereinafter be more fully described, that an infiated tubing of normallyround cross-section passing therethrough is gradually flattened andsimultaneously infolded at the opposite sides thereof to produce theplications. The tubing, as it passes from the discharge `end oftheplicating funnel, is flattened, i. e. the top and bottom panels beingstraight and parallel but slightly spaced from each other with the sidesthereof plicated. The discharge end of the plicating funnel ispositioned in as close proximity as possible to the nip of the secondpair of rolls so that the tubing, as it issues from the plicatingfunnel, will pass quickly to and between the nip of the rolls. Uponpassing between the second pair of rolls, the tubing is completelyflattened, and the attened plicated tubing is wound up on a reel. Theplicating funnel is pivotally mounted at the entrance end thereof, andthe discharge end thereof preferably floats. The internal perimeter ofthe plicating funnel, irrespective of the shape, is of the samemagnitude at all crosssections of the funnel.

The present invention will be more clearly understood by reference tothe following detailed description when taken in connection with theaccompanying drawings, in which:

` Figure 1 is a perspective view, partly broken away and in partdiagrammatic, of one form of an apparatus embodying the principles ofthe invention;

Figure 2 is a top view of the plicating funnel;

Figure 3 is a side view of the plicating funnel;

Figure 4 is a view of the entrance end of the plicating funnel;

' Figure 5 is a section taken on the line 5 5 of Figure 3;

Figure 6 is a section taken on the line 6-6 of Figure;

Figure '7 is a view of the discharge end of the plicating funnel;

Fig-ure 8 is a section taken on the line 8-8 of Figure 1;

tical members l2 and |4 are also secured togetherA` at the bottomthereof by the member 22. Braces 24, 26, 28, 30 are also provided toreinforcethe frame. The two sides of the frame are secured together bycross-pieces 34, 36, 38, 40.

At the feed end of the apparatus, there is provided a pair of squeezerolls 44 and 46. The

roll 44 is secured onto a shaft 48 which is rotatably mounted in a pairof pillow blocks 50. Each pillow block 50 is mounted on a shelf 52secured to vertical supports 54 appropriately secured to thelongitudinal member I0. For

the shaft 48 is provided with a pulley 56 which is driven by a belt 60by a pulley 62 carried on Vthe motor shaft 64 of a motor 66. The motor66 is mounted on a shelf 68 secured to the crosspiece 36.

The roll 46 is secured on a shaft 10, the opposite ends of which arerotatably mounted in bearings 12. Each bearing 12 is provided with agroove 14 on each end thereof and is adapted Vreasons which will becomeapparent, one end of to ride on a pair of spaced vertical rails 16 whichare secured to the member 18 appropriately secured to the members 54.For reasons which will become apparent hereinafter, each of the bearings12 are adapted to be separately and individually raised and lowered. Inthe form shown in Figure l, each bearing 12 is provided with a lug 80which is secured by a pin 82 in a yoke 84 carried at one end of a pistonrod 86.

The piston rod 86 is provided with a piston (not shown) slidablydisposed in an air cylinder 90 having air connections 92 and 64. Eachair cylinder 90 is provided at the top thereof with a forked member 96which is secured to a lug 98 carried by a support |00 secured to the topof the rails 16. Cross-pieces |02 secured to the top of the supports |00reinforce the structure.

At the discharge end of the apparatus, there is provided a second pairof squeeze rolls I|0 and ||2. which is rotatably mounted in pillowblocks ||6. Each pillow block ||6 is carried on a shelf I I8 which, inturn, is carried at the top of the members |20 appropriately mounted onthe longitudinal member |0. On one end of the shaft I|4, there isprovided a pulley |22 which is driven by a belt |24 from a pulley |26carried on the motor shaft |28 of a motor |30. The motor |30 isappropriately mounted on a shelf |32 secured to the longitudinal memberI0. Braces |34 reinforce the shelf |32.

The roll ||2 is secured to a shaft |40, the opposite ends of which arerotatably mounted in bearing blocks |42. Each bearing block |42 isprovided with a groove |44 in each end thereof whereby such bearingblock |42 is adapted to rideon a pair of spaced rails |46 which arecarried on a member |48 supported by the members |50 disposed on theshelf ||8. Each bearing |42 is provided with a lug |52 which is-securedThe roll ||0 is secured on a shaft ||4 y.

4 by a pin |54 in a yoke |56 carried at one end of a piston rod |53. Theother end of the piston rod |58 is secured to a piston (not shown) whichis slidably mounted in a cylinder |62 provided with air connections |64and |66. Each of the cylinders |62 is provided at the top thereof with abifurcated member |68 in which a lug |10 is secured byvmeans of a pin|12. The lug |10 is carried by a member |14, which is secured at the topof the rails |46. Cross-pieces |16 serve to reinforce the structure.

As is 4shown in Figure 1, a plicating funnel, generally indicated"l bythe reference numeral |80, is positioned before the second pair of rollsand in the path of travel of the tubing from the rst tothe second pairof rolls.

The plicating funnel is of a construction such that as an inflatedtubing, substantially circular .incross-section, passes therethrough.said tubing v`will be gradually flattened and the sides thereofsimultaneously infolded to produce a plicated tubing. In general, theplica-ting funnel is circular in cross-section at the entrance endthereof, l. 'as shown in vFigure 4, and the top and bottom 'of' theplicatingfunnel are so shaped that at the of thedischarge opening. Theflat portions |82 of the top and bottom, moreover, converge toward eachother in the direction toward the discharge end but terminate in spacedrelationship, as above explained.

The plicating funnel is also provided with diametrically opposedre-entrant portions |84 in which each of the legs thereof begin in thecircular portion of the funnel and flare inwardly in the directiontoward the discharge end of the funnel. The re-'entrant portions |84, asshown in Figures 5 and 6, are intermediate the top and bottom flatsurfaces I 82 and, at the discharge end, connect the at portionstogether. The inner edges |86 of the re-entrant portions are vpreferablyrounded. The size of the internal perimeter of the plicating funnel isthe same throughout the length of the funnel.

ForY convenience in manufacture, the plicating funnel is formed of twolongitudinal sections which, when positioned with their inner edges inopposed relationship, as hereinafter described, will produce theplicating funnel above described.

The two sections of the funnel are positioned with their inner edges inabutting relationship, and each section of the plicating funnel isrespectively secured at the entrance end of the funnel to a strap |90. Aspring |92 is secured at one end thereof to a pin |94 carried by one ofthe sections, and the other end of the spring is secured to a pin |66carried by the other section. The spring |92 continuously urges thesections toward each other and is preferably disposed in the vicinity ofthe discharge end of the plicating funnel. Y

The plicating funnel is mounted so that it can pivot about a verticalaxis at the entrance end thereof. In the form shown in Figure 1, thestraps are pivotally mounted on a pivot 200 carried by a ring 202. Thering 202 is of greater diameter than the diameter of the entrance end ofthe plicating funnel. The ring 202 is adjustfaseae sa ably mounted inthe apparatus for vreasons which will become apparent hereinafter. Inthe form shown, the ring 202 is .separately secured at two diametricallyopposite points by a bolt 204 to the respective leg 206 of a pair ofbrackets 208. Each bracket 208 is provided with a second leg 2I0 whichis secured, by means of bolts 2I2, to a bracket support 2I4appropriately mounted on the frame of the machine. Each bracket support2I4 is provided with slots 2I6 which cooperate with the bolts 2I2whereby each of the brackets 208 can be adjusted independently of theother. Lock nuts (not shown) cooperate with the bolts 2 I 2 to securethe brackets 208 in adjusted position.

In general, the brackets 208 are adjusted so that the discharge end ofthe funnel will terminate in as close proximity as possible to the nipof the second pair of squeeze rolls. In practice, when the d-iameter ofthe squeeze rolls is the discharge end of the plicating funnel ispositioned approximately from M3 to le" before the nip of the secondpair of feed rolls, with the result that the plicated tubing, as itissues from 'the plicating funnel, is immediately passed between thesecond pair of squeeze rolls and completely flattened thereby.Preferably, the funnel is mounted so that the center of the entrance endthereof is in alignment with the center of the inflated tubing. Due tothe fact that the plicating funnel is supported only at the entrance endthereof, the discharge end thereof floats and the funnel, due to itspivotal mounting, will adjust itself into position so that it will be inthe path of travel of the tubing passing from the rst to the second setof rolls. The diameter of the entrance end of the plicating funnel isapproximately the same as the diameter of the inflated tubing enteringit.

At the beginning of operation of the apparatus,

the rolls 46 and II2 are elevated, and a flattened seamless tubing inwhich the top and bottom panels 220 and 222 are in intimate relationship(see Figure 8) is unwound from a suitable source of supply, such as anappropriately mounted roll 224, and manually threaded through the ma- Ichine, i. e. between the rst set of rolls, through the funnel, andthence between the second set of rolls. The roll 46 is elevated byintroducing compressed air into the air cylinders 90 through the inlets92, whereby the piston rods 86 are moved upwardly with the result thatthe bearings 'i2 carrying the rolls are elevated. The roll I I2 of thesecond pair of squeeze rolls is similarly elevated by introducingrcompressed air in the air cylinders |62 through the 'connections |64,whereby the piston rods 158 are moved upwardly with the result that thebearings carrying the rolls II2 are elevated. The rollf46is then lowereduntil it is in intimate contact with the roll 44 by reversing thedirection of travel of the piston in the air cylinder through 'the-action of compressed air introduced through the inlets 94. Sulicient'air is maintained in the air cylinders to yieldingly mount the'roll 46.

Through the free end of the tubing which extends beyond the second pairof rolls, air is Aintroduced through a "nozzle, connected to anysuitable source of supply, in an Aamount suflicient to inflate thetubing which, prior 'to entrance into the plicating funnel, is circularin cross-section 'j into intimate contact with the roll IIO byintroducing 'compressed air into the air `cylinders `H52 through theinlets I 66 whereby the piston rods 458 descend. The vtwo sets ofsqueeze rolls seal olf or entrap the air in the section of the tubingbetween the hips of the two pairs of squeeze rolls. The motors 66 and|30 are then actuated, with the result that the rolls 44 and 46 unwindthe flattened tubing from the roll 224, and the rolls IIO and II2, whichare driven at the same peripheral speed as the rolls 44 and 46, advancethe tubing through the apparatus. The tubing, prior to passing betweenthe second set of squeeze rolls IIO and II2, passes through theplioatin-g funnel I where it is gradually flattened and simultaneouslyinfolded to produce a plicated tubing conforming to the shape of thedischarge end of the plicating funnel. The tubing, as it passes from theplicating funnel |80, in .introduced lsubstantially immediately betweenthe `nip of the rolls H0 and II2, where it is completely flattened. Theplicated tubing, after passing through the rolls IIO and II 2, is of theform .shown in Figure 10, wherein the legs .225 ofthe plications are ofequal length. The collapsed plicated tubing is then wound up on atake-up roll 230, which is driven by any wellknown compensating drive,so that the peripheral speed of the wind-up surface will be the same asthe linear speed of the tubi-ng passing through the machine. Due to thefact that the two sets of squeeze Vrolls and the take-up roll are drivenat the same peripheral speed throughout the process, the tubing is notstretched.

VIt is to be noted that when the tubing is continuously fed between thetwo pairs of squeeze rolls, the entrapped gaseous medium advances bodilytherethrough while remaining 4substantially constant in quantity. Whenfor some reason or other the quantity of the gaseous .medium decreases,as by loss through leakage, additional gaseous vmedium may be introducedto 'compensate therefor.

The apparatus can be operated at various speeds. Satisfactory resultshave been obtained when the tubing is fed through the apparatus at 'aspeed 'as high as 60 'feet per minute and as low as 5` feet per minute.

The distance between the 'two sets of squeeze rolls can Vary within Widelimits and is not critical. The two sets of squeeze rolls can be spaced2 feetapart or any greater distance desired.

In the preferred embodiment of the invention, the upper idler rolls 46and II2 are preferably formed with a rubber surface, and the lowerdriven rolls 44 and IIO are formed of any suitable material, such aspolished steel.

The plicating funnel is preferably formed of highly polished sheetmetal. Due to the fact that the magnitude of the inner perimeter of theplicating funnel is the same at all cross-sections,

there is no excess of material and a product free of wrinkles isobtained.

`'Ihough in the rpreceding embodiment the plicated tubing (see Figure10) has legs of equal length, the invention is not restricted thereto.By making the legs of the re-entrant `portions of the plicating funnelof unequal lengths, the legs of the flattened plicated tubing can bemade of unequal lengths. In Figure 11 wherein such an embodiment isshown, the legs 240 are of greater length than the legs 242.

- Ingeneral, the apparatus and the method can be utilized for theproduction of plicated seamiesstubing formed of any material which issub- V7 stantially impervious to the gaseous medium employed for theinflation. Seamless tubing 'formed of regenerated cellulose or ofplastics, such as cellulose acetate, cellulose acetobutyrate, ethylcellulose, methyl Inethacrylate polymer, extrusion or molding'grade ofnylon, polystyrene, polyvinyl formal-acetatebutyral, copolymer of vinylchloride and vinyl acetate, polyvinyl chloride, and copolymer of vinylchloride and vinylidene chloride are illustrative examples of tubingwhich can be plicated by this invention.

Though air is the preferred gaseous inating medium, it is to beunderstood that any other gaseous medium which is inert with respect tothe material constituting the tubing can be used.

The invention is not restricted to pneumatic means for actuating theroll-raising mechanism. If desired, hydraulic actuating means can beused. Likewise, the upper rolls of each set of squeeze rolls can beyieldingly mounted in any other suitable manner, as, for example,through the use of springs.

In the embodiment hereinbefore described, the tubing was plicated as ittravelled in a horizontal path. The invention is equally vapplicable totubing travelling in a vertical or inclined path.

Likewise, the rolls 44 and l lll can be driven from` a common drive.

Though the invention has been described in connection with theproduction of plicated seamless tubing from preformed flattened seamlesstubing, the invention is not restricted thereto. The apparatusconstituting one phase of this invention can be used in combination witha tubeproducing machine whereby the tubing will be plicated in anoperation combined with the method of producing the tubing. Theinvention provides a method of and apparatus for producing continuouslengths of plicated tubing, something which has been long sought in theart. The plicated tubing can be used as such or transversely cut intopredetermined lengths and one end thereof sealed to provide a bag.

Since it is. obvious that various changes and modiiications can be madein the above description without departing from the nature or spiritthereof, this invention is not restricted thereto except as set forth inthe appended claims.

I claim:

1, An apparatus for producing continuous lengths of plicated tubingwhich comprises a first pair of squeeze rolls, a second pair of squeezerolls disposed in spaced relationship to said rst pair, both pairs ofsqueeze rolls being adapted to seal oli a gaseous medium introduced in asection of a tubing extending from the rst set of squeeze rolls to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from the :irstset to the second set of squeeze rolls and the gaseous medium advancesbodily therethrough while remaining substantially .constant in quantity,a plicating funnel positioned in the path of travel of the tubingbetween said squeeze rolls and having its discharge end disposed inclose proximity to the nip of the second pair of squeeze rolls, saidplicating funnel having means to gradually flatten and simultaneouslyinfold tubing at opposite sides thereof and means pivotally mountingsaid funnel adjacent its entrance end only.

2. An apparatus for producing continuous lengths of plicated -tubingwhich comprises a iirst pair of squeeze rolls, a second pair of squeeze'rolls'disposed'in spaced relationship to said first pair, 'both pairsof squeeze rolls being adapted to seal ofi a gaseous medium introducedin a section of a tubing extending from the rst set of squeeze rolls tothe second set of squeeze rolls, means to continuously rotate each pairof squeeze rolls-whereby the tubing is continuously passed from theiirst set to the second set of squeeze -rolls and the gaseous mediumadvances bodily squeeze rolls disposed in spaced relationship to saidfirst pair, both pairs of squeeze rolls being adapted to seal off agaseous medium introduced in a section of a tubing extending from thefirst set of squeeze rolls to the second set of squeeze rolls, means tocontinuously rotate each pair of squeeze rolls whereby the tubing iscontinuously passed from the first set to the second set of squeezerolls and the gaseous medium advances bodily therethrough whileremaining substantially constant in quantity, a plicating funnel togradually hatten and simultaneously infold the tubing, means topivotally mount said plicating funnel only adjacent the entrance endthereof whereby the discharge end floats, and means to adjust saidplicating funnel relative to the second pair of squeeze rolls.

4. An apparatus for producing continuous lengths of plicated tubingwhich comprises a iirst pair of squeeze rolls, a second pair of squeezerolls disposed 'in spaced relationship to said rst pair, both pairs ofsqueeze rolls being adapted to seal o a gaseous medium introduced in asection of a 'tubing extending from the rst set of squeeze rolls'to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from'the rst setto the second set of squeeze rolls and the gaseous medium advancesbodily therethrough While remaining substantially con- -stant inquantity, a plicating funnel to gradually flatten and simultaneouslyinfold the tubing, a support adjacent the entrance end of said plicatingfunnel, means to pivotally mount said funnel on said support whereby thedischarge end of said funnel oats, and means to adjustably mount saidsupport.

5. An apparatus for producing continuous lengths of plicated tubingwhich comprises a rst pair of squeeze rolls, a second pair of squeezerolls disposed in spaced relationship to said iirst pair, both pairs ofsqueeze rolls being adapted to seal off a gaseous medium introduced in asection of a tubing extending from the rst set of squeeze rolls to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from the firstset to the second set of squeeze rolls and the gaseous medium advancesbodily therethrough while remaining substantially constant in quantity,a plicating funnel to gradually flatten and simultaneously infold thetubing, a ring support in whichr the entrance end of said plicatingfunnel is positioned, means pivotally mount` ing said funnel to` saidring support, a pair of brackets secured to opposite sides of said ringsupport, a pair of bracket supports, and means to adjustably positioneach bracket in its respective support.

6. An apparatus for producing continuous lengths of plicated tubingwhich comprises a rst pair of squeeze rolls, a second pair of squeezerolls disposed in spaced relationship to said first pair, both pairs ofsqueeze rolls being adapted to seal oi a gaseous medium introduced in asection of a tubing extending from the iirst set of squeeze rolls to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from the rst setto the second set of squeeze rolls and the gaseous medium advancesbodily there-4 through while remain substantially constant in quantity,a plicating funnel, means to dispose said funnel inthe path of travel ofthe tubingbetween said squeeze rolls with its discharge end in closeproximity to the nip of the second pair of squeeze rolls, and means topivotally mount said plicating funnel at its entrance end only wherebythe discharge end floats, said plicating funnel having its top andbottom each formed with a iiat surface which iiares in the direction oftravel of the tubing therethrough, said flat surfaces also converging inthe directionA of travel of the tubing through said funnel butterminating in spaced relationship, and said plicating funnel having apair of diametrically opposed reentrant portions, the legs of whichflare inwardly in the direction of travel of the tubing through saidfunnel. i

7. An apparatus for producing continuous lengths of plicated tubingwhich comprises a rst pair of squeeze rolls, a second pair of squeezerolls disposed in spaced relationship to said rst pair, both pairs ofsqueeze rolls being adapted to seal 01T a gaseous medium introduced in asection of a tubing extending from the rst set of squLeze rolls to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from the rst setto the second set of squeeze rolls and the gaseous medium advancesbodily therethrough while remaining substantially constant in quantity,a plicating funnel formed of two longitudinal sections, a supportadjacent the entrance end of said funnel, means to pivotally mount theentrance end of said sections on said support, means urging saidsections toward each other, and means to adjustably mount said supportwhereby said funnel can be adjusted to desired position, said plicatingfunnel having its top and bottom each formed with a iiat surface whichares in the direction of travel of the tubing therethrough, said iiatsurfaces also converging in the direction of travel of the tubingthrough said funnel but terminating in spaced relationship, saidplicating funnel having a pairof diametrically opposed re-entractportions, the legs of which nare inwardly in the direction of travel ofthe tubing through said funnel.

8. An apparatus for producing continuous lengths of plicated tubingwhich comprises a iirst pair of squ-eze rolls, a second pair of squeezerolls disposed in spaced relationship to said first pair, both pairs ofsqueeze rolls being adapted to seal 01T a gaseous medium introduced in asection of a tubing extending from the rst set of squeeze rolls to thesecond set of squeeze rolls, means to continuously rotate each pair ofsqueeze rolls whereby the tubing is continuously passed from the firstset to the second set of squeeze rolls and the gaseous medium advancesbodily therethrough while remaining substantially constant in quantity,a plicating funnel formed of two longitudinal sections, a supportadjacent the entrance end of said funnel, means to pivotally mount saidsections on said support, yieldable means adjacmt the discharge end ofsaid funnel continuously urging said sections toward each other, andmeans to adjustably position said support, said plicating funnel havingits top and bottom each formed with a flat surface which flares in thedirection of travel of the tubing therethrough, said flat surfaces alsoconverging in the direction of travel of the tubing through said funnelbut terminating in spaced relationship, and said plicating funnel havinga pair of diametrically opposed re-entrant portions, the legs of whichnare inwardly in the direction of travel of the tubing through saidfunnel.

9. An apparatus for producing continuous lengths of plicated tubingcomprising means to seal 01T a gaseous medium in a section of seamlesstubing whereby said gaseous medium is isolated therein and said sectioncontains only and is iniiated solely by said gaseous medium, said meansincluding a pair of rotating squeeze rolls at the forward end of theisolated gaseous medium for advancing said tubing and retaining saidgaseous medium in said tubing whereby the gaseous medium advances bodilythrough the said advancing tubing while remaining substantially constantin quantity, means providing a forwardly tapering passage through whichthe successively inflated sections are passed and whereby said actionsare gradually flattened, the discharge end of said forwardly taperingpassage being in close proximity to the nip of said pair of rotatingsqueeze rolls, and means infolding the tubing at opposite sides as itpasses through 'said passage, the flattening and infolding means beingdisposed in the path of travel of the tubing to said squeeze rolls.

GUSTAV FREUND, II.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 331,721 Lorenz et al Dec. 1, 1885465,211 Schenck Dec. 15, 1891 2,346,187 Reichel Apr. 11, 1944 FOREIGNPATENTS Number Country Date Y 686,952 Germany Jan. 19, 1940

